Spading machine



Feb. 23,1965

H. VISSERS 3,170,522

SPADING MACHINE Filed Au 5, 1963 s Sheets-Sheet 1 I N VEN TOR. /ER-EEFTWSSHK Feb. 23, 1965 H. VISISERS 3,170,522

SPADING MACHINE' Filed Aug. 5, 1963 v 3 Sheets-Sheet 2 Feb. 23, 1965 H. VISSERS 3,170,522

SPADING MACHINE Filed Aug. 5, 1963 s Sheets-Sheet z INVENTOR.

United States Patent C) 3,170,522 SPADING MACHINE Herbert Vissers, Spoorstraat 4, Nieuw-Veunep, Netherlands Filed Aug. 5, 1963, Ser. No. 300,009 Claims. (Cl. 172--91) The invention relates to a spading machine, comprising a number of spading blades which are radially disposed about a hub, the said blades having a substantially involute profile, said spading blades being capable of rotating together around the center line of the hub but each of them being capable to be tilted individually about a stub axle, which is supported in the hub, the center line of the said stub axle being situated susbtantially in a plane which is perpendicular to a radius of the hub. Such a machine is known from the patent application Serial Number 470,086, now Patent No. 3,120,279. In most cases the spading blades form a number of spading units arranged one beside another, each unit being composed of a hub and three spading blades.

In practice, however, it has been found that some disadvantages are connected with this known spading machine, as for instance owing to the fact that the deposited clod of earth tends to get partially in the adjacent furrow instead of in its own one. The magnitude of this phenomenon increases rapidly when the operative speed of the machine is increased.

This results in that the more or less laterally deposited clod of earth can hamper the undisturbed action of the spading blade just rising from the soil and belonging to the adjacent unit. This inconvenience has so far been remedied by applying two measures, viz. a moderate operational speed, while in addition the tilting movement of each spading blade is started as late as possible, so that the spades of the adjacent unit have already moved upwardly to an extent so as to be not hindered by the adjacent deposited clod of earth.

It is an object of the invention to eliminate the cause of the inconvenience described above and to construct the machine in such a Way that the clods of earth land in their own furrow.

The invention further aims to reduce the angle, which is enclosed by the free end of the'spading blade and the direction of travel (in the tilted position), so that the velocity can be enhanced without the risk of a clod of earth landing entirely or partially outside of its own furrow.

An important object of the invention consists in designing a spading machine adapted to shift the starting moment of the tilting movement of each spading blade to a possibly earliest time without any risk of hindering the operation of a spading blade of an adjacent spading unit. This advanced start of the tilting movement is advantageous in some respects. It will for instance be possible to throw sooner the clod of earth from the spading blade, whereby the next spading blade of the same spading unit remains still far outside the path of the clod of earth and in this respect, too, there is less risk of disturbance. There is further more time available for the tilting movement of each spading blade, so that this movement can last through a greater angle of arc of the rotation of the spading unit. This means that smaller acceleration forces are produced.

A still further object of the invention consists in improving the way in which the clods of earth are deposited, that is the position of the clods of earth which are successively deposited in the furrow. So far it has been found that often the clods of earth did not well close up owing to which open spaces between the clods of earth were formed whereby the rain water for instance could quickly drain away. Moreover these open spaces "ice are disadvantageous with a view to a subsequent working of the soil (e. g. harrowing and sowing).

A further inconvenience of the known spading machine consists in that during the penetration into the soil the reaction force of the soil and of the dug out clod of earth on the spading blade produces a tilting torque in the spading blade, the valve of this reaction torque increasing when the said blade is tilted. Such a tendency gives rise to a certain instability in the operation of the machine as the spading blade on a minor deviation from its correct spading position is subjected to an increase of this disturbing tilting reaction torque.

Therefore the invention further aims at utilizing the reaction torque exerted by the soil on the spading blades for stabilising the correct spading position of the blade by designing the machine such that a minor tilting of the spade element causes an increase of the torque exerted on the spading blade, which torque tends to return the blade to its correct spading position.

Other and further objects and advantages, of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a side elevation of a spading unit.

FIGURE 2 is a front view of the unit according to FIGURE 1.

FIGURE 3 is a plan view of a spading unit with a tilted spading blade of which the tilting axle is practically parallel to the plane of drawing.

As is visible in FIG. 1 the spading unit represented therein consists of three spading blades 2 which are radially arranged about a hub 1, the said blades being capable of rotation around the center line 3 of the hub. Each spading blade 2 consists of a rod 4 which is bent so as to be substantially involute, a blade 5 being secured on the said rod. At the end of this blade is a cutting strip 6 with the cutting edge 7 proper. The rod 4 is supported for tilting in the hub 1 by means of an axle stub 8, the center line 9 of which is situated in a plane which is substantially perpendicular to a radius of the hub.

The situation of the cutting edge 7 is such that the elongated center line 9 of the associated tilting axle 8 passes through the cutting edge 7 or lies within a distance from the elongated center line 9 which is equal to half the distance e between the elongated center line 9 and the center line 3 of the hub (see FIG. 1). This configuration applies to both the tilted and the untilted spading position of the spading blade 2. The length and the shape of each spading blade 2 is such that the cutting edge 7 is either intersecting the elongated center line 9 or lies somewhat in front of or somewhat behind this line 9, within the region indicated in FIG. 1 as plus or minus e/2. As indicated in the sixth paragraph of the specification above, the described configuration has the advantage of shifting the start of tilting to the earliest possible time as compared to the construction of earlier patent such as 3,120,279 and 3,012,616, in which the cutting edge lies ahead of center line 9 by a distance approximately equal to 2.

According to an embodiment, see FIG. 1, the cutting edge 7 may slightly trail in respect of the rotary movement, indicated by an arrow P, in relation to the elongated center line 9, whereby the stability of each spading blade during its penetration into the soil is enhanced since the arm of the tilting couple resulting from ground resistance decreases when tilting begins rather than increases as when the cutting edge lies ahead of the center line 9.

As appears from FIG. 2 the left portion of the blade 5 and particularly of the cutting edge 7 has a width which 3 is equal to a third of the overall width of this blade. This left portion of the blade or cutting edge is the side which rises when the spading blade is tilted and which therefore is to impart the tilting movement to the just dug out clod of earth resting on the blade. An increased Width of this left part of the blade at the costs of the right hand portion can result in that the clod of earth is deposited too far sideways. When the left portion is narrowed there is on the contrary a risk that the tilting thrust imparted to the clod of earth concerned is too small, so that the clod is not deposited in the furrow in a position which is tilted through 90.

It has just been indicated that the ratio between the portions of the blade 5 situated on either side of the rod 4 has to be carefully adapted to the result aimed at of the spading effect of the machine. The same applies to the choice of the width of each blade 5 in respect of the operative depth of the machine. These two dimensions should be about of the same order of magnitude. This is due to the fact that the clod of earth after having been dug out is again deposited in the furrow in a tilted position. In the event a broad blade 5 would be employed with a small spading depth, the deposited clods of earth would partially emerge from the original level of the mowing field which inevitably results in that the edgewise positioned clods of earth are interspaced whereby the dreaded open deposit of the clods of earth would appear, if on the contrary the spading depth exceeds the width of the spading blade the tilted clods of earth do no longer fit in the narrow furrow.

Also the pitch of each clod of earth, that is to say the spacing between the points of penetration into the field of two successive spading blades is to be considered, although it is of slightly less importance. In relation to an embodiment which in practice yields favourable results the following dimensions can be mentioned.

Pitch length: 11 to 12 inch Operative depth: 12 to 13 inch Width of spade: about 14 inch 7 As is visible in FIG. 3 the shaping of the spading blade and especially of the rod 4 is such that the outer portion of the concave side of the spading bladeas contemplated in plan view, the tilting axle being situated practically horizontally and the spading blade being in the tilted position-coincides substantially with the side of the furrow 11 dug by this unit. The spading blade 2 represented in plan view, moves upwardly in this situation that is to say toward the onlooker (see the direction of rota-tion P). Such a situation is also determined by the width of the left portion of the spading'blade 5 and the cutting strip 6 described hereinbefore and visible in FIG. 2, the width being a third of the entire width of the blade 5.

On working with a spading unit constructed in such 'a way the dug out clod of earth can readily glide down and land in its own furrow so that in respect of the known device an increase of operational speed is possible without the risk of the clods of earth landing in a wrong place. Furthermore the deposit of the clods of earth is improved and a more uniformly closed surface of the field is obtained after the spading operation has been performed.

Represented in the drawing is onlya single spading unit, it is, however, usual to apply a number of adjacent units on a common hub (shown in dotted lines inFIG- URE 2) whereby a spading operation over 'a broad front'becomes possible.

Although the present invention has been disclosed. in connection with a few preferred embodiments thereof, variations and modifications maybe resorted to by those skilled in the art without departing from the principles of the invention, as disclosed in the foregoing description and defined by the appended claims.

What I claim is:

1. A spading machine, comprising .a number of spading blades of .involute profile radially disposed about a hub, each of said blades being rotata-bl'y mounted on a stub axle supported in the hub for individual tilting with respect to the hub while rotating together with the other blades around the center line of the hub, the center line of each said stub axle being situated substantially in a plane which is perpendicular to a radius of the hub, and each spading blade having a cutting edge which, both in the tilted and untilted condition of the blade, lies within a distance from the elongated center line of its stub axle which is at most equal to half the distance between said elongated center line and the center line of the hub.

2. A spading machine according to claim 1, wherein when said stub axle is substantially horizontal and the spading blade is in the tilted position the outer portion of the concave side of each spading blade when viewed in a vertically downward direction substantially coincides with the side of the furrow just dug.

3. A spading machine according to claim 1, wherein said cutting edge of each blade lies in the trailing side of the elongated center line of said stub axle with respect to the rotary movement of the hub;

4. A spading machine according to claim 1, wherein said cutting edge and spading blade are mounted asymmetrical-1y with respect to said stub axle, the latter being offset in the direction toward the side of the blade which tilts upwardly.

5. A spading machine according to claim 4, wherein said stub axle is mounted at a distance from the side of the'blade equal to approximately one third the width of the blade.

References Cited by the Examiner V UNITED STATES PATENTS 2,603,139 7/52 Johnson 172-544 3,012,616 12/61 Horowitz 17295 X T. GRAHAM CRAVER, Primary Examiner, 

1. A SPADING MACHINE, COMPRISING A NUMBER OF SPADING BLADES INVOLUTE PROFILE RADIALLY DISPOSED ABOUT A HUB, EACH OF SAID BLADES BEING ROTATABLY MOUNTED ON A STUB AXLE SUPPORTED IN THE HUB FOR INDIVIDUAL TILTING WITH RESPECT TO THE HUB WHILE ROTATING TOGETHER WITH THE OTHER BLADES AROUND THE CENTER LINE OF THE HUB, THE CENTER LINE OF EACH SAID STUB AXLE BEING SITUATED SUBSTANTIALLY IN A PLANE WHICH IS PERPENDICULAR TO A RADIUS OF THE HUB, AND EACH SPADING BLADE HAVING A CUTTING EDGE WHICH, BOTH IN THE TILTED AND UNTILTED CONDITION OF THE BLADE, LIES WITHIN A DISTANCE FROM THE ELONGATED CENTER LINE OF ITS STUB AXLE WHICH IS AT MOST EQUAL TO HALF THE DISTANCE BETWEEN SAID ELONGATED CENTER LINE AND THE CENTER LINE OF THE HUB. 